Re: [HACKERS] Problem with the numbers I reported yesterday - Mailing list pgsql-hackers

From Boersenspielteam
Subject Re: [HACKERS] Problem with the numbers I reported yesterday
Date
Msg-id 199802121443.PAA22726@www.vocalweb.de
Whole thread Raw
In response to Re: [HACKERS] Problem with the numbers I reported yesterday  (Bruce Momjian <maillist@candle.pha.pa.us>)
Responses Re: [HACKERS] Problem with the numbers I reported yesterday  (Bruce Momjian <maillist@candle.pha.pa.us>)
List pgsql-hackers
Hi,

perhaps a stupid question:

What will happen, if you start PostgreSQL with -F and write a script
which is a loop that fsyncs every 2 seconds? Does this lead to a
database which is "almost" correct? Does this seem like a good
compromise?

> > I ran my performance tests some more times and it seems the numbers are not
> > really comparable. When I run PostgreSQL without -F I get a sync after every
> > insert. With -F I get no sync at all as all inserts fit well into the
> > buffer. However, Oracle in comparison does sync. Simply hearing the disk
> > access it seems as if they sync every two or three seconds.
> >
> > Does anyone know a way to really check both DBMSs?
>
> Many dbms's do buffered logging, that is they sync after the buffer gets
> full or after a minute or so.  We have the logic to add buffered logging
> to PostgreSQL and will be doing it later.  Right now, we only have
> non-buffered logging, and no logging.
>
> --
> Bruce Momjian
> maillist@candle.pha.pa.us
>
>

Ciao

Das Boersenspielteam.

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